Scanning force microscopy (SFM) has been used for the determination of friction, phase transformation, piezoelectric behavior (in the contact mode), polarization state, and dielectric constant (in the noncontact mode) of nanometer regions of lead zirconate titanate (PZT) films. The use of the SFM tip in the contact mode, to polarize different nanoregions of the PZT film and to apply an oscillating field thereon, led to effective piezoelectric coefficients and piezoelectric loops. The measured effective piezoelectric coefficient was shown to depend appreciably on both the tip contact force and the quality of the tip-to-film electrical contact. In the noncontact mode, application of an ac signal (with a frequency ω) across the tip—PZT film—electrode system produced an oscillation of the tip at frequencies ω (fundamental or first harmonic) and 2ω (second harmonic). The signals at ω and 2ω were related to the state of polarization and the dielectric constant of the PZT film, respectively. Analysis of the combined contact, noncontact and friction force microscopic data provided insight into the structure and into the dielectric, ferroelectric, and piezoelectric properties of distinct nanoregions of the PZT film.

The use of virtual reality in education has enabled the possibility of representing abstract concepts and virtually manipulating them, providing a suitable platform for understanding mathematical concepts and their relation with the physical world. In this contribution, we present a study that aims to evaluate the students’ experience using a virtual reality (VR) tool and their learning of three-dimensional vectors in an introductory physics university course. We followed an experimental research design, with a control and an experimental group, for measuring students’ performance in a pre-post 3D vectors questionnaire. We surveyed the experimental group about their perception of VR use regarding their learning objectives, their experience using VR as a learning tool during the sessions, and the value of using VR in class. We found that on the items in which visualization was important, students in the experimental group outperformed the students in the control group. Students evaluated the VR tool as having a positive impact on their course contents learning and as a valuable tool to enhance their learning experience. We identified four hierarchical categories in which students perceived the use of virtual reality helped them learn the course contents: Visualization, 3D Visualization, Identification, and Understanding. Overall, this study’s findings contribute to the knowledge of using virtual reality for education at the university level. We encourage university instructors to think about incorporating VR in their classes.

Development and testing of the test of understanding of vectors.

Teaching by subjects and contents where students passively receive knowledge is increasingly obsolete. Universities are opting for teaching strategies supporting skills development to face the labor, social, environmental, and economic conditions afflicting us. Employers demand increasingly complex skills; universities have identified experiential learning as giving access to real situations and learning by doing. One of the most advanced strategies is Challenge-Based Learning (CBL). Through real problem situations, faculty and students collaborate to solve an established challenge, with or without external stakeholders. This educational advancement has been global and is developing graduates with international skills, which ensures a world-class standard. Here we report a global study carried out in universities from three different continents, and we analyze the implementations of CBL in educational programs through cases in Mexico, The Netherlands, Ireland, and China. Developing skills and competencies is evident, and CBL is a viable way to ensure the success of Higher Education graduates. Obstacles in the transformation of faculty towards CBL are a similar fence in all cases. For CBL, the path needs to be explored, as it is on the frontline of educational developments that can be most helpful for developing a new paradigm in education.

In this article, we present several modifications to the Test of Understanding Graphs in Kinematics. The most significant changes are (i) the addition and removal of items to achieve parallelism in the objectives (dimensions) of the test, thus allowing comparisons of students’ performance that were not possible with the original version, and (ii) changes to the distractors of some of the original items that represent the most frequent alternative conceptions. The final modified version (after an iterative process involving four administrations of test variations over two years) was administered to 471 students of an introductory university physics course at a large private university in Mexico. When analyzing the final modified version of the test it was found that the added items satisfied the statistical tests of difficulty, discriminatory power, and reliability; also, that the great majority of the modified distractors were effective in terms of their frequency selection and discriminatory power; and, that the final modified version of the test satisfied the reliability and discriminatory power criteria as well as the original test. Here, we also show the use of the new version of the test, presenting a new analysis of students’ understanding not possible to do before with the original version of the test, specifically regarding the objectives and items that in the new version meet parallelisms. Finally, in the PhysPort project (physport.org), we present the final modified version of the test. It can be used by teachers and researchers to assess students’ understanding of graphs in kinematics, as well as their learning about them.